1. Field of the Invention
The present invention relates to a filament winding apparatus.
2. Description of the Related Art
A well-known filament winding apparatus includes a hoop winding unit and a helical winding unit and forms reinforced layers by alternately performing a hoop winding operation by the hoop winding unit and a helical winding operation by the helical winding unit repeatedly on a liner and thus winding fiber bundles around the liner.
When the helical winding unit performs the helical winding operation, the liner moves in an axial direction while being rotated at constant speed, and the fiber bundle is supplied from the helical winding unit and wound around the liner. In a conventional art, when the fiber bundle is wound around the liner, the fiber bundle is guided from a guide portion of the helical winding unit to the liner (for example, refer to JP 2000-108212A).
However, some liners have a smaller radius at both end portions than at a central portion. When the fiber bundle is wound around such liners, a distance from the liner to the guide portion varies between the case of winding the fiber bundle around the end portions and the case of winding the fiber bundle around the central portion. When the distance from the liner to the guide portion varies, a tension of the fiber bundle fluctuates, resulting in fluctuations in the winding operation, i.e., an amount of wound fiber bundle varies depending on a position of the liner.
In view of the above, an apparatus has been developed that reduces the fluctuations in the winding operation by approximating the guide portion in a radius direction of the liner and by resultantly reducing the variation (an amount of change) of the distance between the liner and the guide portion when the portion to have the fiber bundle wound around changes from the central portion to the end portions of the liner.
However, a plurality of guide portions are usually provided around the liner. As a result, leading end portions of the guide portions collide and interfere with each other when the guide portions are moved in the radius direction of the liner to be close to the liner, and therefore, there are limitations to the reduction of the variation of the distance from the liner to the guide portions.